Generate bridges for trait implementations properly

The intent was to keep the bridge codegen model as simple as possible: we
should be able to figure out all necessary bridges only by a minimal interface
that FunctionHandle provides (isAbstract, isDeclaration, getOverridden)

Add different tests for bridges

 #KT-318 Obsolete

compiler/testData/codegen/box/bridges/fakeOverrideInTraitWithRequiredFromTraitImpl.kt

@@ -0,0 +1,17 @@
+abstract class A {
+    abstract fun foo(): Any
+}
+
+trait B {
+    fun foo(): String = "B"
+}
+
+trait C : A, B
+
+class D : A(), C
+
+fun box(): String {
+    val d = D()
+    val r = d.foo() + (d : C).foo() + (d : B).foo() + (d : A).foo()
+    return if (r == "BBBB") "OK" else "Fail: $r"
+}